Currently nutritional changes are a public health problem in all over the world, affecting all age groups including young adults. While the under nutrition is affecting one side, over nutrition is also affecting the people on the other side. This leads to obesity. Levels of overweight and obesity together with other cardiovascular risk factors increase with age even within this age span[1]. The Study aims the Correlation between RBC and it’s indices in Students of Osmania Medical College with different body mass indices and look for correlation between BMI and RBC and it’s indices. A cross-sectional study was conducted in 100 healthy individuals with different body mass indices in the age group of 18-35yrs. Subjects were divided into 4 categories on BMI. 2ml venous blood collected in EDTA containers. It is analysed in automatic Haemocytometer. Pearson correlation was done to find the correlation between BMI & RBC and it’s indices. Pearson correlation was done to find the correlation between BMI & RBC and it’s indices. In the study there was significant positive correlation between BMI and RBC, negative correlation between BMI and MCV, MCH, MCHC. Individuals with high BMI have increased RBC count & low RBC indices.